[unreadable] Oral delivery remains the preferred route for drug administration. However, therapeutic macromolecular drugs currently under development suffer from poor oral bioavailability. Microfabrication technology may offer potential advantages over conventional drug delivery stratagems. This technology, combined with appropriate surface chemistry, can permit highly localized delivery of drugs and permeation enhancers. In this proposal, we investigate microfabrication strategies to create reservoir-containing microdevices and a surface chemistry protocol that can be used to bind muco- or cytoadhesives to these platforms. The long-term objective of this proposal is to develop a biomedical microsystem for oral delivery of pharmacologically active macromolecules into the systemic circulation via the creation of a robust hybrid organic/inorganic delivery system. It is expected that the proposed drug delivery system will enable directional release at the lumen-enterocyte interface resulting in elevated local concentrations. The central hypothesis to our proposed research is that the penetration potential of poorly permeable drugs is significantly enhanced by increasing both the epithelial residence time and local concentration. We propose the following specific aims: [unreadable] 1. To asymmetrically conjugate bioadhesive ligands to microdevices [unreadable] 2. To determine the in vitro release mechanism of drug-loaded microsystems [unreadable] 3. To compare the permeation enhancement effects of bioadhesive microdevices against established oral drug delivery standards [unreadable] 4. Test microdevices in vivo for their ability to deliver therapeutically relevant amounts of drug. [unreadable] We expect to find that microdevices can exhibit enhanced biocompatibility and bioadhesion due to our ability to control device architecture in terms of bulk material, shape, size, and surface chemistry. This may allow for the delivery of multiple therapeutic macromolecules in a more controlled and targeted manner to the GI tract. [unreadable] [unreadable]